Arlene Foster announced on Wednesday that she is resigning as First Minister of Northern Ireland and leader of the Democratic Unionist Party (DUP).
Foster said in a statement that her resignations would be effective on May 28 for the DUP leadership and at the end of June as First Minister.
The 51-year-old became DUP leader in 2015 and first served as First Minister in 2016. But in recent weeks, she has been facing strong criticism from inside the party with most of her lawmakers reportedly signing a letter calling for her removal.
The revolt is believed to be linked to Brexit and the Northern Ireland Protocol, which effectively creates a border in the Irish Sea between Northern Ireland and Britain.
"It has been the privilege of my life to serve the people of Northern Ireland as the First Minister," she wrote.
She defended her legacy, recognising however that "there have been ups and downs", and called for greater devolution.
"As I prepare to depart the political stage it is my view that if Northern Ireland is to prosper then it will only do so on the foundations of successful and durable devolution. That will require continued hard work and real determination and courage on all sides," she wrote.
She also mentioned the Northern Ireland Protocol, which she said had been "foisted upon" the British province "against the will of unionists" and which "has served to destabilise Northern Ireland in recent times".